This invention relates to multiple interconnected stents or stent segments, the interconnections being comprised of lengths of a plastic material. The term xe2x80x9cplasticxe2x80x9d is used herein to refer to materials which are capable of being deformed permanently without rupture.
In the prior art, stents are well known for use in opening and reinforcing the interior wall of blood vessels and other body conduits.
Stents are generally tubular, radially expandable and may be of the self-expanding type or may be expandable with an outward pressure applied to the stent, typically by expansion of an interiorly positioned balloon. Stents are made of various materials such as plastic or metal, metal usually being preferred.
Since stents must be of somewhat rigid design to provide reinforcement support and may be required to be of considerable length in order to extend over a lengthy area, it is difficult to resolve this need for rigidity with the need of having a flexible stent which is readily implanted by inserting it through a sometimes tortuous curving path as is often encountered in the percutaneous insertion technique typically used for implantation of stents. This is further complicated by the fact that stents must be readily expandable upon implantation to provide a support structure.
It is known that a plurality of stent elements can be loosely interconnected together by filaments or the like to provide a lengthy flexible stent arrangement. Such arrangements are shown in the following patents for example:
U.S. Pat. No. 5,405,377 to Cragg
U.S. Pat. No. 5,665,115 to Cragg
U.S. Pat. No. 5,755,781 to Jayaraman
U.S. Pat. No. 5,443,476 to Schwartz et al.
U.S. Pat. No. 5,135,536 to Hillstead
U.S. Pat. No. 5,035,706 to Gianturco et al.
WO 93/13825 (PCT) to Maeda et al.
The following technical literature is also of interest in this regard:
Tracheobronchial Tree: Expandable Metallic Stents Used in Experimental and Clinical Applications, Work in Progress; Radiology, February 1986, pp 309-312.
Experimental intrahepatic Portacaval Anastomosis: Use of Expandable Gianturco Stents; Radiology, February 1987, 162: 481-485.
Gianturco Expandable Wire Stents in the Treatment of Superior Vena Cava Syndrome Recurring After Maximumxe2x80x94Tolerance Radiation; Cancer, September 1987, Vol. 60, pp 1243-1246.
Modified Gianturco Expandable Wire Stents in Experimental And Clinical Use; Cerise, Porto Cervo, May 1987, pp 100-103.
This invention is directed to an improvement in the general concept of joined stents or stent segments (hereinafter referred to collectively as xe2x80x9cstent segmentsxe2x80x9d) in which a xe2x80x9cplasticxe2x80x9d material (capable of exhibiting permanent deformation) extends between stents or stent segments (hereinafter referred to collectively as stent segments) to interconnect them with a somewhat constrained freedom of motion relative to each other, i.e., not loosely connected but flexibly connected. The stent segments are preferably of closed cell design and even more preferably of the self-expanding type. More precisely, the interconnecting elements are of a material different than the stent material and are plastically deformable.